Nuprl Lemma : integer-sqrt-ext

x:ℕ(∃r:ℕ [(((r r) ≤ x) ∧ x < (r 1) (r 1))])


Proof




Definitions occuring in Statement :  nat: less_than: a < b le: A ≤ B all: x:A. B[x] sq_exists: x:A [B[x]] and: P ∧ Q multiply: m add: m natural_number: $n
Definitions unfolded in proof :  member: t ∈ T exp: i^n primrec: primrec(n;b;c) subtract: m fastexp: i^n efficient-exp-ext so_apply: x[s1;s2] natrec: natrec genrec: genrec genrec-ap: genrec-ap integer-sqrt integer-nth-root div_nat_induction rem_bounds_1 decidable__lt decidable__equal_int decidable__squash decidable__and decidable__less_than' decidable__int_equal decidable_functionality squash_elim sq_stable_from_decidable any: any x iff_preserves_decidability sq_stable__from_stable stable__from_decidable uall: [x:A]. B[x] so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]) so_apply: x[s1;s2;s3;s4] so_lambda: λ2x.t[x] top: Top so_apply: x[s] uimplies: supposing a implies:  Q has-value: (a)↓ prop:
Lemmas referenced :  integer-sqrt lifting-strict-int_eq strict4-decide lifting-strict-decide lifting-strict-less cbv_sqequal has-value_wf_base efficient-exp-ext integer-nth-root div_nat_induction rem_bounds_1 decidable__lt decidable__equal_int decidable__squash decidable__and decidable__less_than' decidable__int_equal decidable_functionality squash_elim sq_stable_from_decidable iff_preserves_decidability sq_stable__from_stable stable__from_decidable
Rules used in proof :  introduction sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity cut instantiate extract_by_obid hypothesis sqequalRule thin sqequalHypSubstitution equalityTransitivity equalitySymmetry isectElimination baseClosed isect_memberEquality voidElimination voidEquality independent_isectElimination baseApply closedConclusion hypothesisEquality lambdaFormation callbyvalueReduce

Latex:
\mforall{}x:\mBbbN{}.  (\mexists{}r:\mBbbN{}  [(((r  *  r)  \mleq{}  x)  \mwedge{}  x  <  (r  +  1)  *  (r  +  1))])



Date html generated: 2018_05_21-PM-07_52_25
Last ObjectModification: 2018_05_19-PM-04_50_03

Theory : general


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